Adaptive receive diversity during discontinuous reception in mobile wireless device

ABSTRACT

A mobile wireless device adapts receive diversity during discontinuous reception based on downlink signal quality, page indicators and page messages. When the downlink signal quality exceeds a pre-determined threshold, the mobile wireless device decodes a page indicator channel through an initial antenna, and otherwise, decodes a paging channel through the initial antenna without decoding the page indicator channel. The mobile wireless device switches to decoding the paging channel through an alternate antenna when a page indicator decodes as an erasure. When a paging message received through a single antenna decodes with an incorrect error checking code, the mobile wireless devices enables receive diversity through multiple antennas for subsequent decoding. The mobile wireless device switches between single antenna reception and multiple antenna reception based on tracking multiple consecutive error checking code failures and successes.

TECHNICAL FIELD

The described embodiments generally relate to methods and apparatusesfor adapting receive diversity for mobile wireless devices. Moreparticularly, the present embodiments describe selective use of receivediversity for mobile wireless devices with multiple receivers andmultiple antennas during discontinuous reception modes.

BACKGROUND

Mobile wireless devices in wireless networks can be designed to balanceadvanced communication capabilities with limited available powerstorage, particularly in devices with smaller form factors that offer“high performance” features such as provided in “smart” phones. Analogsignal reception and signal processing by the mobile wireless device canconsume significant amounts of power when active that can affect batterydrain in the mobile device. Continuous reception of radio frequencysignals, even when not establishing or maintaining an active connectionwith the wireless network, can reduce the operating time of the mobilewireless device unnecessarily. In an “idle” state, during which themobile wireless device may not be not actively connected to the wirelessnetwork, the mobile wireless device can receive and process signalsselectively rather than continuously to reduce power consumption. Activecircuitry in the mobile wireless device can be limited to componentsneeded to receive and decode signaling messages from the wirelessnetwork. Wireless communication standards can specify procedures thatcan provide for lower power consumption by allowing the mobile wirelessdevice to cycle between a non-active “sleep” state and an active “wake”state in a process known as discontinuous reception (DRX). Newer mobilewireless devices can also include multiple antennas connected tomultiple receivers that can each consume power. During an active wakecycle, the mobile wireless device can selectively receive signalsthrough one or more antennas, adapting the number of antennas used andthe number of active receivers that process signals based on receivedsignal conditions to balance performance of wireless reception withlocal battery power consumption.

Wireless networks continue to evolve as new communication technologiesdevelop and standardize. Current wireless network deployments includemany variations in architecture, including support for differentwireless communication technologies offered by one or more wirelessnetwork service providers. A representative wireless network for awireless network service provider can include support for one or morereleases of wireless communication protocols specified by the ThirdGeneration Partnership Project (3GPP) and Third Generation PartnershipProject 2 (3GPP2) communication standards organizations. The 3GPPdevelops mobile communication standards that include releases for GlobalSystem for Mobile Communications (GSM), General Packet Radio Service(GPRS), Universal Mobile Telecommunications System (UMTS), Long TermEvolution (LTE) and LTE Advanced standards. The 3GPP2 develops mobilecommunication standards that include CDMA2000 1×RTT standards. Each ofthe standards listed above include a form of discontinuous reception(DRX) in which one or more receivers (or transceivers) in a mobilewireless device can be disabled periodically to save power consumptionand then be selectively enabled to listen for signaling messagestransmitted by the wireless network. The signaling messages can be usedto initiate connections between the specific mobile wireless device andthe wireless network as well as to broadcast information to multiplemobile wireless devices for operation in the wireless network.

Representative signaling messages include paging indicators sent in oneor more paging indicator channels and paging messages (or more generallysignaling/control messages) transmitted in parallel paging(signaling/control) channels. The mobile wireless device can monitor apaging channel directly or can monitor a paging indicator channel forpaging indicators that can point to a forthcoming paging message on apaging channel As a paging indicator can be as short as one bit,variations in received signal quality conditions can corrupt the pageindicator bit and can potentially result in the mobile wireless devicemissing page messages or reading page messages intended for other mobilewireless devices and thus wasting power consumption in the mobilewireless device unnecessarily. The mobile wireless device can adaptreception based on measured receive signal quality and/or receive signalstrength to improve reception of the signaling messages. The mobilewireless device can enable multiple receivers to improve signalreception of paging indicators on the paging indicator channel and/orpaging messages on the paging channel. For mobile wireless devices thatsupport receive diversity with multiple antennas and multiple receivers,power consumption during signal reception can depend on the number ofactive receivers. The performance of decoding received can depend on thequality of signals received through one or more antennas, each of whichcan be connected to one or more receivers. Thus there exists a need formethods and apparatuses to adapt receive diversity in a mobile wirelessdevice that can improve signal reception while limiting powerconsumption during discontinuous reception in the wireless network.

SUMMARY OF THE DESCRIBED EMBODIMENTS

In one embodiment, a method of adapting receive diversity in a mobilewireless device is described. The method includes at least the followingsteps. During a discontinuous reception cycle, a mobile wireless devicedecodes page indicators and/or page messages through one or moreantennas. When a measured downlink signal quality exceeds apre-determined threshold, the mobile wireless device decodes at leastone page indicator received on a page indicator channel through theinitial antenna. When the measured downlink signal quality does notexceed the pre-determined threshold, the mobile wireless device decodesthe paging channel using the initial antenna without decoding pageindicators on the page indicator channel When the first page indicatordecodes as an erasure, the mobile wireless device decodes a page messagereceived on a paging channel through an alternate antenna. When themobile wireless device decodes page messages through the initial antennaor through the alternate antenna alone and no received page messagedecodes with a correct error checking code, the mobile wireless devicedecodes one or more page messages using receive diversity through theinitial antenna and through the alternate antenna together.

In another embodiment, a mobile wireless device includes a firstreceiver, a second receiver, a first antenna, a second antenna, a switchand a configurable processor. The switch interconnects the first andsecond receivers to the first and second antennas. The processor isconfigured to switch signal reception of a paging channel between thefirst antenna and the second antenna based on decoding of a receivedpage indicator on a page indicator channel. The processor is furtherconfigured to enable signal reception through both the first and secondantennas and signal processing in the first and second receiversfollowing decoding an incorrect error checking code in a paging messagereceived on the paging channel. The processor is also configured tore-enable signal reception through only one of the first and secondantennas and only one of the first and second receivers followingdecoding of multiple correct error checking codes on multipleconsecutive paging messages received on the paging channel.

In a further embodiment, non-transitory computer program product encodedin a non-transitory computer readable medium of adapting receivediversity in a mobile wireless device is described. The non-transitorycomputer program product in the mobile wireless device includes at leastthe following non-transitory computer program code. Non-transitorycomputer program code for enabling reception of signaling messagesthrough one antenna and one receiver or through more than one antennaand more than one receiver based on measurements of received downlinksignal quality. Non-transitory computer program code for choosingthrough which antenna and through which receiver to receive thesignaling messages based on measurements of downlink signal strengthreceived through each antenna. Non-transitory computer program code forswitching from single antenna reception to multiple antenna receptionfollowing multiple consecutive error checking code failures on receivedsignaling messages. Non-transitory computer program code for switchingfrom multiple antenna reception to single antenna reception followingmultiple consecutive error checking code successes on received signalingmessages.

Although described in terms of a generic wireless network and a specificCDMA2000 1× wireless network, the embodiments disclosed herein can beextended to include other wireless networks such as GSM/GPRS, UMTS, LTEand LTE Advanced networks as well.

BRIEF DESCRIPTION OF THE DRAWINGS

The described embodiments and the advantages thereof may best beunderstood by reference to the following description taken inconjunction with the accompanying drawings.

FIG. 1 illustrates components of a generic wireless communicationnetwork.

FIG. 2 illustrates components of a UMTS wireless communication network.

FIG. 3 illustrates components of a CDMA2000 1× wireless communicationnetwork.

FIG. 4 illustrates components of a LTE wireless communication network.

FIG. 5 illustrates a representative architecture for a mobile wirelesscommunication device.

FIG. 6 illustrates a state transition diagram for a mobile wirelesscommunication device in a wireless network.

FIG. 7 illustrates a state transition diagram for a mobile wirelesscommunication device during system acquisition of a wireless network.

FIG. 8 illustrates a paging indicator channel and a paging/controlchannel for a CDMA2000 1× wireless network.

FIG. 9 illustrates a slotted mode discontinuous reception cycle for amobile wireless device receiving a paging/control channel in a CDMA20001× wireless network.

FIG. 10A illustrates a format for paging messages on a paging channel ina CDMA2000 1× wireless network.

FIG. 10B illustrates a format for control messages on a control channelin a CDMA2000 1× wireless network.

FIG. 11 illustrates two configurations for a dual pole dual throw switchin a mobile wireless device that supports receive diversity.

FIG. 12 summarizes page/control channel actions for a mobile wirelessdevice based on decoded page indicator values.

FIGS. 13A and 13B illustrate a representative method for adaptingreceive diversity for a mobile wireless device in a CDMA2000 1× wirelessnetwork.

FIGS. 14-19 illustrates another representative method for adaptingreceive diversity for a mobile wireless device in a CDMA2000 1× wirelessnetwork.

DETAILED DESCRIPTION OF SELECTED EMBODIMENTS

In the following description, numerous specific details are set forth toprovide a thorough understanding of the concepts underlying thedescribed embodiments. It will be apparent, however, to one skilled inthe art that the described embodiments may be practiced without some orall of these specific details. In other instances, well known processsteps have not been described in detail in order to avoid unnecessarilyobscuring the underlying concepts.

The examples and embodiments provided below describe various methods andapparatuses for adapting receive diversity in a wireless mobile device,and in particular to selective use of receive diversity for the mobilewireless device operating with multiple antennas and multiple receiversduring discontinuous reception cycles. It should be understood thatimplementations of the same methods and apparatuses described herein canapply to mobile wireless devices used in different types of wirelessnetworks. For example, the same teachings can be applied to a GSMnetwork, a UMTS network, an LTE network or other wireless network thatuses discontinuous reception. In general, the teachings described hereincan apply to a mobile wireless device operating in a wireless networkbased on radio access technology. The specific examples andimplementations described herein are presented for simplicity inrelation CDMA2000 1× networks but also can apply to other wirelessnetwork environments.

Mobile wireless devices can offer advanced communication capabilities,including increasing data transfer speeds, access to multiple types ofwireless networks and robust performance in the presence of varyinglevels of noise and interference. At the same time, manufacturers of amobile wireless device can seek to improve “stand-by” time of the mobilewireless device by minimizing power consumption from limited batterystorage available within the mobile wireless device. Thus, a balancebetween robust performance and power consumption can be sought. Toimprove signal reception performance, the mobile wireless device caninclude multiple receivers interconnected to multiple antennas. Signalsreceived on different antennas in the same mobile wireless device caneach provide different signal quality levels and different signalstrengths depending on the antennas' locations as well as an orientationof the mobile wireless device with respect to a transmitting radioaccess system in the wireless network. In addition, interveningobstructions that can block and reflect transmitted signals cansignificantly affect signal reception at the mobile wireless device. Themobile wireless device can select to use one of a plurality of antennasand receivers based on signal and decoding measurements. The mobilewireless device can also enable receive diversity selectively to receivesignals through more than one of the plurality of antennas as requiredto provide reliable reception of critical signaling messages receivedfrom the wireless network. Measurements of received downlink signalstrength and/or received downlink signal quality can be used by themobile wireless device to select among the plurality of antennas andwhen to use one or multiple antennas.

Continuous reception through one or more sets of analog receivecircuitry in the mobile wireless device can consume significantly morepower than selective discontinuous reception of signals received duringperiods when the mobile wireless device is not actively connected to themobile wireless network. When using a non-slotted mode, the mobilewireless device can listen continuously on a signaling channel forsignaling messages that can be used to initiate establishment of anactive connection between the mobile wireless device and the wirelessnetwork. Representative signaling messages can include paging messagestransmitted on a paging channel. As signaling channels, such as thepaging channel, can be shared among multiple mobile wireless devices,the wireless network can divide transmissions on the signaling channelinto individual slots and can assign to each mobile wireless devicewithin a limited geographic area covered by a radio sector (cell) of thewireless network a time slot in which to listen for paging messages onthe paging channel. Thus, the mobile wireless device can preferentiallylisten for signaling messages during assigned time slots rather thanlisten continuously. This selective listening can be referred to asoperating in a slotted mode. In addition, the mobile wireless device candisable one or more receivers in the mobile wireless device during timeslots not assigned to the mobile wireless device, the mobile wirelessdevice can reduce power consumption by operating in the slotteddiscontinuous reception mode rather than the non-slotted continuousreception mode.

In certain wireless networks, such as a CDMA2000 1× network, a separatesignaling channel, e.g. a paging indicator channel, can provide anindication to the mobile wireless device of a signaling (paging) messageforthcoming on the parallel paging channel Paging indicators on the pageindicator channel can be significantly shorter and easier to decode thanpaging messages, and thus by listening for shorter transmissions on thepaging indicator channel with simpler circuitry rather than for longertransmissions directly on the paging channel with more complexcircuitry, the mobile wireless device can further reduce powerconsumption when there is no paging message intended for the mobilewireless device. When the mobile wireless device receives a positiveindication on the paging indicator channel, the mobile wireless devicecan listen for a subsequent paging message on the paging channel Incontrast, when the mobile wireless device receives a negative indicationon the paging indicator channel, the mobile wireless device can skiplistening to the paging channel and return to a sleep state to conservepower.

Messages received on the paging indicator channel can be quite short,for example only one bit in length, and can be interpreted as a positiveindication, a negative indication or an indefinite indication of apaging message addressed to the mobile wireless device on the pagingchannel. The mobile wireless device can measure downlink signal qualityand can selectively listen to the paging indicator channel when themeasured downlink signal quality exceeds a pre-determined threshold.Under good received signal conditions, a single bit indicator on thepaging indicator channel can provide a reliable indication of thepresence of paging messages for the mobile wireless device on the pagingchannel When the measured downlink signal quality does not exceed thepre-determined threshold, however, the mobile wireless device can listendirectly to the paging channel instead and can ignore the pagingindicator channel, as single bits received on the paging indicatorchannel with poor signal conditions can provide an unreliable indicationof the availability of paging messages. The paging indicator channel caninclude multiple copies of paging indications to improve reliablereception. The mobile wireless device can choose to listen for one ormore of the multiple copies of the paging indicators. The mobilewireless device can also select to receive signals from differentantennas based on interpreted values for one or more indicator bitsreceived on the paging indicator channel. When an indicator bit receivedthrough one antenna can be interpreted as “indefinite”, the mobilewireless device can choose to receive another copy of the indicator bitthrough a different antenna in order to provide a clearer indication offorthcoming paging messages.

Each paging message received on the paging channel can include an errorchecking code, e.g. a cyclic redundancy check (CRC), that can confirmintegrity of the data contained in the paging message. When unable tolocate a paging message with a “good” CRC on the paging channel for apre-determined period of time, or after receiving a pre-determinednumber of consecutive paging messages with incorrect error checkingcodes, i.e. with “bad” CRC, the mobile wireless device can enablereception through multiple antennas and receivers simultaneously, i.e.full receive diversity, in order to improve signal reception in thepresence of noise and interference. Full receive diversity can providemore reliable signal reception when receive signal conditions are poor,while single antenna and single receiver reception can provide reducedpower consumption when receive signal conditions are good. Full receivediversity can be used for reception of signals on the paging channel,while single antenna and single receiver reception can be used forsignals received on both the paging indicator channel and the pagingchannel

These and other embodiments are discussed below with reference to FIGS.1-15. However, those skilled in the art will readily appreciate that thedetailed description given herein with respect to these figures is forexplanatory purposes only and should not be construed as limiting.

FIG. 1 illustrates a representative generic wireless communicationnetwork 100 that can include multiple mobile wireless devices 102connected by radio links 126 to radio sectors 104 provided by a radioaccess network 128. Each radio sector 104 can represent a geographicarea of radio coverage emanating from an associated radio node 108 usinga radio frequency carrier at a selected frequency. Radio sectors 104 canhave different geometric shapes depending on a transmission antennaconfiguration, such as radiating outward in an approximate circle orhexagon from a centrally placed radio node 108 or cone shaped for adirectional antenna from a corner placed radio node 108. Radio sectors104 can overlap in geographic area coverage so that the mobile wirelessdevice 102 can receive signals from more than one radio sector 104simultaneously. Each radio node 108 can generate one or more radiosectors 104 to which the mobile wireless device 102 can connect by oneor more radio links 126. To form a mobile terminated connection betweenthe mobile wireless device 102 and the radio access network 128, a radiocontroller 110 in the radio access subsystem 106 can instruct the radionode to transmit a signaling message, such as a page message, to themobile wireless device 102. In certain networks, the radio controller110 can also instruct the radio node to transmit a signaling indicator,such as a page indicator bit, in advance of the page message to providenotice to the mobile wireless device 102 of the forthcoming pagemessage. Upon reception of the page message, and following an additionalexchange of signaling messages with the radio access network 128, themobile wireless device can form an active connection with the wirelessnetwork 100.

In some wireless networks 100, the mobile wireless device 102 can beconnected to more than one radio sector 104 simultaneously. The multipleradio sectors 104 to which the mobile wireless device 102 is connectedcan come from a single radio node 108 or from separate radio nodes 108that can share a common radio controller 110. A group of radio nodes 108together with the associated radio controller 110 can be referred to asa radio access subsystem 106. Typically each radio node 108 in a radioaccess subsystem 106 can include a set of radio frequency transmittingand receiving equipment mounted on an antenna tower, and the radiocontroller 110 connected to the radio nodes 108 can include electronicequipment for controlling and processing transmitted and received radiofrequency signals. The radio controller 110 can manage theestablishment, maintenance and release of the radio links 126 thatconnect the mobile wireless device 102 to the radio access network 128.

The radio access network 128, which provides radio frequency air linkconnections to the mobile wireless device 102, connects also to a corenetwork 112 that can include a circuit switched domain 122, usually usedfor voice traffic, and a packet switched domain 124, usually used fordata traffic. Radio controllers 110 in the radio access subsystems 106of the radio access network 128 can connect to both a circuit switchingcenter 118 in the circuit switched domain 122 and a packet switchingnode 120 in the packet switched domain of the core network 112. Thecircuit switching center 118 can route circuit switched traffic, such asa voice call, to a public switched telephone network (PSTN) 114. Thepacket switching node 120 can route packet switched traffic, such as a“connectionless” set of data packets, to a public data network (PDN)116.

FIG. 2 illustrates a representative UMTS wireless communication network200 that can include one or more user equipment (UE) 202 that cancommunicate with a UMTS terrestrial radio access network (UTRAN) 242that can connect to a core network (CN) 236. The core network 236 caninclude a circuit switched domain 238 that can connect the UE 202 to apublic switched telephone network (PSTN) 232 and a packet switcheddomain 240 that can connect the UE 202 to a packet data network (PDN)234. The UTRAN 242 can include one or more radio network sub-systems(RNS) 204/214 each of which can include a radio network controller (RNC)208/212 and one or more Node-Bs (base stations) 206/210/216 managed by acorresponding RNC. The RNC 208/212 within the UTRAN 242 can beinterconnected to exchange control information and manage packetsreceived from and destined to the UE 202. Each RNC 208/212 can handlethe assignment and management of radio resources for the cells 244through which the UE 202 connect to the wireless network 200 and canoperate as an access point for the UE 202 with respect to the corenetwork 236. In order to establish a connection, the RNC 208/212 cancommunicate with the UE 202 through an associated Node-B 206/210/216using a series of signaling messages. The Node-B 206/210/216 can receiveinformation sent by the physical layer of UE 202 through an uplink andtransmit data to UE 202 through a downlink and can operate as accesspoints of the UTRAN 242 for UE 202.

UTRAN 242 can construct and maintain a radio access bearer (RAB) forcommunication between UE 202 and the core network 236. Services providedto a specific UE 202 can include circuit switched (CS) services andpacket switched (PS) services. For example, a general voice conversationcan be transported through a circuit switched service, while a Webbrowsing application can provide access to the World Wide Web (WWW)through an internet connection that can be classified as a packetswitched (PS) service. To support circuit switched services, the RNC208/212 can connect to the mobile switching center (MSC) 228 of corenetwork 236, and MSC 228 can be connected to gateway mobile switchingcenter (GMSC) 230, which can manage connections to other networks, suchas the PSTN 232. To support packet switched services, the RNC 208/212can also be connected to serving general packet radio service (GPRS)support node (SGSN) 224, which can connect to gateway GPRS support node(GGSN) 226 of core network 236. SGSN 224 can support packetcommunications with the RNC 208/212, and the GGSN 226 can manageconnections with other packet switched networks, such as the PDN 234. Arepresentative PDN 234 can be the “Internet”.

FIG. 3 illustrates a representative CDMA2000 wireless network 300 thatcan include elements comparable to those described earlier for thegeneric wireless network 100 and the UMTS wireless network 200. Multiplemobile stations 302 can connect to one or more radio sectors 304 throughradio frequency links 326. Each radio sector 304 can radiate outwardfrom a base transceiver station (BTS) 308 that can connect to a basestation controller (BSC) 310, together forming a base station subsystem(BSS) 306. Multiple base station subsystems 306 can be aggregated toform a radio access network 328. Base station controllers 310 indifferent base station subsystems 306 can be interconnected. The basestation controllers 310 can connect to both a circuit switched domain322 that use multiple mobile switching centers (MSC) 318 and a packetswitched domain 324 formed with packet data service nodes (PDSN) 320,which together can form a core network 312 for the wireless network 300.As with the other wireless networks 100/200 described above, the circuitswitched domain 322 of the core network 312 can interconnect to the PSTN114, while the packet switched domain 324 of the core network 312 caninterconnect to the PDN 116.

FIG. 4 illustrates a representative Long Term Evolution (LTE) wirelessnetwork 400 architecture designed as a packet switched networkexclusively. A mobile terminal 402 can connect to an evolved radioaccess network 422 through radio links 426 associated with radio sectors404 that emanate from evolved Node B's (eNodeB) 410. The eNodeB 410includes the functions of both the transmitting and receiving basestations (such as the Node B 206 in the UMTS network 200 and the BTS 308in the CDMA2000 network 300) as well as the base station radiocontrollers (such as the RNC 212 in the UMTS network 200 and the BSC 310in the CDMA2000 network 300). The equivalent core network of the LTEwireless network 400 is an evolved packet core network 420 includingserving gateways 412 that interconnect the evolved radio access network422 to public data network (PDN) gateways 416 that connect to externalinternet protocol (IP) networks 418. Multiple eNodeB 410 can be groupedtogether to form an evolved UTRAN (eUTRAN) 406. The eNodeB 410 can alsobe connected to a mobility management entity (MME) 414 that can providecontrol over connections for the mobile terminal 402.

FIG. 5 illustrates select elements for an architecture 500 that can beused for a mobile wireless device 102. The mobile wireless device 102can include a first transceiver 504 that can process signals accordingto a first wireless communication protocol and a second transceiver 506that can process signals according to a second wireless communicationprotocol. The first and second wireless communication protocols can beidentical or can be different. Circuitry for and capabilities of thefirst transceiver 504 and the second transceiver 506 can be identical orcan be different. In a representative embodiment, the first transceiver504 can transmit and receive wireless signals while the secondtransceiver can only receive but not transmit wireless signals. Thefirst transceiver 504 can be interconnected to the second transceiver506 to provide control information between them enabling coordinatedtransmission and reception to minimize interference. Both the firsttransceiver 504 and the second transceiver 506 can be connected to anapplication processor (AP) 502 that can provide higher layer functions,such requesting establishment and release of connections for variousresident application services. Establishment of connections can includereception of signaling messages such as paging messages received througheither of the transceivers 504/506 individually or through bothtransceivers 504/506 simultaneously. The transceivers 504/506 canprovide lower layer functions such as reliable bit level transmissionand reception that can support the communication of data messages forhigher layer services controlled by the application processor 502.

The first transceiver 504 can be connected to a first antenna 508 or toa second antenna 510, and the second transceiver 506 can be connectedsimilarly to the first antenna 508 or the second antenna 510 through adual pole dual throw (DPDT) switch 512. The use of multiple antennas forwireless communication protocols can provide improved performance (e.g.higher data rates or better immunity to interference) compared to asingle antenna configuration. One of the antennas can provide a strongersignal than the other antenna, or both antennas can be used to receivesignals simultaneously in order to improve signal reception and decodingin the mobile wireless device 102. The DPDT switch can operate in one oftwo positions, either a “straight through” connection or a “crossed”configuration. Using the DPDT switch 512, either transceiver 504/506 canbe connected to either antenna 508/510. Each transceiver 504/506 can beconnected to a single antenna 508/510 at one time, and both transceivers504/506 can be connected to separate antennas 508/510 and not beconnected to the same antenna 508/510 simultaneously.

FIG. 6 illustrates a high level state transition diagram 600 for themobile wireless device 102 (and for the mobile station 302 operating inthe CDMA2000 wireless network 300) when associating and connecting withthe wireless network 100. The mobile wireless device 102 can initiallybe disconnected from the wireless network 100 and be in a powered offstate 602. After powering on, the mobile wireless device 102 can enteran initialization state 604 during which the mobile wireless device 102can locate one or more radio sectors 104 (or equivalently cells) in thewireless network 100 with which the mobile wireless device 102 canassociate and connect. The mobile wireless device 102 can know afrequency band in which to receive transmissions and can identify radiosectors 104 by searching for physical channels, such as pilot signals,broadcast by the wireless network 100. The mobile wireless device 102can register with the wireless network 100 to indicate its presence andthereby alert the wireless network 100 to its availability to initiateand to receive (terminate) connections.

After acquiring the wireless network 100, the mobile wireless device 102can enter an “idle” state 606. For wireless networks 100 that supportpower saving modes, the idle state 606 can include periods of time inwhich portions of the mobile wireless device 102 can be powered down.The mobile wireless device 102 can be powered up during appropriate timeintervals known to wireless network 100 in which to receive a pagemessage from the wireless network. The page messages can includeinformation broadcast to multiple mobile wireless devices 102 in thewireless network as well as specific messages intended for theparticular mobile wireless device 102. After receiving a page message,the mobile wireless device 102 can enter a system access state 608during which it can establish radio resources with the wireless network100 over which to communicate traffic (voice/video/data/messages) withthe wireless network 100 in a traffic active state 610. The activeconnection can subsequently be disconnected by the mobile wirelessdevice 102 or the wireless network 100 and the mobile wireless device102 can return from the traffic active state 610 to the idle state 606to await pages for a future connection.

FIG. 7 illustrates a set 700 of sub-states through which the mobilewireless device 102 can traverse when executing the initialization state604 of FIG. 6. After power up from the power off state 602, the mobilewireless device 102 can enter the system determination sub-state 702. Inthe system determination sub-state 702, the mobile wireless device 102can select a wireless network 100 as a wireless system to use. Followingthe selection of the wireless network 100 system, the mobile wirelessdevice 102 can acquire the selected wireless network 100 system bysearching for and acquiring a pilot channel in the pilot channelacquisition sub-state 704. Once the pilot channel is acquired, themobile wireless device 102 can enter a sync channel acquisitionsub-state 704. If no pilot channel is acquired by the mobile wirelessdevice 102 within a pre-determined period of time while in the pilotchannel acquisition sub-state 704, the mobile wireless device 102 canreturn to the system determination sub-state 702 indicating a pilotacquisition failure. Following successful pilot acquisition, the mobilewireless device 102 can obtain system configuration and timinginformation from the wireless network 100 in the sync channelacquisition sub-state 704. Once sync channel acquisition is complete,the mobile wireless device 102 can enter the timing adjustment sub-state708 and can synchronize timing in the mobile wireless device 102 withthe selected wireless network 100. When system acquisition is complete,the mobile wireless device 102 can enter the idle state 606 and canmonitor one or more signaling channels for signaling messages sent bythe wireless network 100. In a representative CDMA2000 wireless networkembodiment, the mobile station 302 in the idle state 606 can monitor oneor more channels that can include a paging channel (PCH), a quick pagingchannel (QPCH), a forward common control channel (F-CCCH) and a primarybroadcast control channel (PBCH). The mobile station 302 can monitor thequick paging channel for page indicators that can determine when themobile station 302 should listen to a parallel paging channel or forwardcommon control channel for signaling messages. By listening to the quickpaging channel during limited short time intervals only, the mobilestation 302 can conserve power in the idle state 606 by powering downselect internal components, such as analog receive circuitry, when notlistening to the quick paging channel

FIG. 8 illustrates a representative slotted mode 800 transmission schemefor the mobile station 302 operating in the CDMA2000 1× wireless network300. Transmissions on a paging channel (F-PCH) or a forward commoncontrol channel (F-CCCH) can be divided into a series of equal durationtime slots 804. Each PCH/F-CCCH slot 804 can extend for 80 ms, and aseries of 2048 successive PCH/F-CCCH slots 804 can span a maximum slotcycle length of 2048×80 ms=163.84 seconds. The mobile station 302 candetermine a slot number in the integer range from 0 to 2047 based on apre-determined algorithm and can also determine a slot cycle lengthequal to T multiples of 1.28 seconds where T=2^(i), and the integer i isa slot cycle index taken from a set of the integer values, e.g. {0, 1,2, 3, 4, 5, 6, 7}. For example, with a slot cycle index i=0, the mobilestation 302 can be assigned slots 804 spaced 1 multiple of 1.28 s=16×80ms time slots apart. With a slot cycle index i=2, the mobile station 302can be assigned slots 804 spaced 2²=4 multiples of 1.28 s=64×80 ms timeslots apart. When operating in a slotted mode in an idle state, themobile station 302 can listen to the assigned PCH/F-CCCH time slots 804and can sleep during the intervening PCH/F-CCCH time slots 804 toconserve battery power. As an assigned PCH/F-CCCH time slot 804 can beassigned to multiple mobile stations 302 in the wireless network 300,the wireless network 300 can also transmit indicators on a quick pagingchannel (QPCH) 806 parallel to the paging channel The indicators on theQPCH 806 channel can communicate to individual mobile stations 302 aboutthe availability of a forthcoming message on the parallel PCH/F-CCCH 802channel.

As shown in FIG. 8, the QPCH 806 channel can be divided into successive80 ms QPCH slots 822 (each QPCH slot 822 having the same length as acorresponding PCH/F-CCCH slot 804), and each QPCH slot 822 can bedivided into four contiguous 20 ms time intervals 808. Indicatorscommunicated in a QPCH slot 822 on the QPCH 806 channel can alert themobile station 302 of the availability of signaling messages intendedfor the mobile station 302 in a subsequent PCH/F-CCCH slot 804 on thePCH/F-CCCH 802 channel In a representative embodiment, the indicatortransmitted in the QPCH slot 822 can be a single bit, which can berepeated in two separate non-contiguous time intervals 808 of the QPCHslot 822. The mobile station 302 can monitor paging indicators in theassigned quick paging channel slots 822, which can be offset in advanceof the associated PCH/F-CCCH slot 804. Two paging indicators can betransmitted in either QPCH intervals 1 and 3 or in QPCH intervals 2 and4 of the QPCH slot 822. A first QPCH page indicator PI1 810 for a firstmobile station 302 (MS 1) can be transmitted in QPCH interval 1 andrepeated as a second page indicator PI2 812 for the first mobile station302 (MS 1) in QPCH interval 3. Similarly a first QPCH page indicator PI1810 for a second mobile station 302 (MS 2) can be transmitted in QPCHinterval 2 and repeated as a second page indicator PI2 812 for thesecond mobile station 302 (MS 2) in QPCH interval 4. The wirelessnetwork 300 can also transmit broadcast indicators (BCST IND) 818 andconfiguration change indicators (CONFIG CHG IND) 820 in the QPCH slot822. The broadcast and configuration change indicators can be directedto all mobile stations 302 currently associated with a radio sector 304in the wireless network 300.

The mobile station 302 can monitor the paging indicators 810/812 in anassigned QPCH slot 822 of the QPCH channel 806, and when the mobilestation 302 detects an “OFF” paging indicator bit value, the mobilestation 302 can forgo monitoring the associated PCH/F-CCCH slot 804 ofthe PCH/F-CCCH 802 channel. When the mobile station 302 detects an “ON”paging indicator bit value in both the first paging indicator bit 810and in the second paging indicator bit 812, the mobile station 302 canmonitor the associated PCH/F-CCCH slot 804 of the PCH/F-CCCH 802 channelfor a paging (control/signaling) message. When the mobile station 302detects an “ERASURE” paging indicator bit value (i.e. neither anunequivocal “ON” or unequivocal “OFF”), the mobile station 302 canmonitor the associated PCH/F-CCCH slot 804 on the PCH/F-CCCH 802channel, as the paging indicator bit value detected can be equivocal,neither indicating a presence nor indicating an absence of a signalingmessage on the immediately following PCH/F-CCCH slot 804 on thePCH/F-CCCH 802 channel Monitoring paging indicator bits 810/812 on theQPCH channel 806 can conserve battery power, as the mobile station 302can avoid monitoring the PCH/F-CCCH channel 802 when no intendedsignaling message exists. Monitoring for one or two bits on the QPCHchannel 806 can consume less processing power than monitoring for anentire signaling message on the PCH/F-CCCH 802 channel

FIG. 9 illustrates a slotted mode 900 of operation for a mobile station302 on a PCH/F-CCCH 802 channel with a slot cycle 908 of 16 consecutivetime slots. In a representative example as show, the mobile station 302can be assigned the time slots numbered 2/18/34/ . . . in successiveslot cycles 908. When not monitoring the PCH/F-CCCH 802 channeldirectly, the mobile station 302 can “sleep” for most slots and “awaken”to reacquire the wireless network 300 to monitor the assigned slot inthe slot cycle 908. The mobile station 302 can be in a non-active state902 outside of the assigned and immediate preceding PCH/F-CCCH 802channel slots. For example, during slot 1, the mobile station 302 canawaken from a sleep state and can re-acquire the wireless network 300prior to monitoring for and receiving a signaling message during slot 2of the PCH/F-CCCH channel 802. After receiving signals during theassigned slot, the mobile station 302 can return to the non-active state902 and can later repeat the re-acquisition and reception for theassigned slot in each successive slot cycle 908 on the PCH/F-CCCH 802channel When monitoring an associated QPCH channel 806 (not shown), themobile station 302 can sleep, re-acquire and receive indicator bits onthe QPCH channel 806 in a similar manner to the slotted cyclic modedepicted in FIG. 9 for the PCH/F-CCCH 802 channel. When received pagingindicator bits so indicate, the mobile station 302 can receive signalingmessages in the associated time slot on the PCH/F-CCCH channel 802.(When the indicator bits are inconclusive, the mobile station 302 canalso monitor the time slot in the PCH/F-CCCH channel 802 so as to notmiss inadvertently an intended paging message.) When the indicator bitsreceived on the QPCH channel 806 indicate no message on the PCH channel,then the mobile station 302 can avoid reading the PCH channel and cansleep in the non-active state 902 until the next slot cycle 908.

FIG. 10A illustrates a format 1000 for transmitting a layer 2 signalingPCH message 1006 in a PCH slot 1014 on the PCH/F-CCCH channel 802. Thelayer 2 signaling PCH message 1006 can also be referred to as a layer 2encapsulated protocol data unit (PDU). The PCH slot 1014 can includeeight half-frames, each half-frame occupying 10 ms of the 80 ms PCH timeslot 1014. Each half-frame can include a synchronized capsule indicator(SCI) bit 1004, which can indicate the start (SCI=1) or continuation(SCI=0) of the PCH message 1006, followed by a half-frame body. Multiplehalf-frame bodies from separate half-frames can be assembled together toform a single PCH message 1006. Within a single PCH time slot 1014,multiple PCH messages 1006 can be contained. The PCH message 1006 can beformatted as shown in FIG. 10A to include a length segment 1008, a bodysegment 1010 and a layer 2 cyclic redundancy check (CRC) segment 1012.The length segment 1008 can indicate the number of bits/bytes in the PCHmessage 1006, while the CRC segment 1012 can provide an error checkingcapability. The mobile station 302 can calculate a CRC based on thereceived PCH body 1010 and can compare the calculated CRC to thereceived CRC segment 1012. The calculated CRC can match the received CRCsegment 1012, which can be considered a “correctly” received CRC, i.e. aCRC “Pass” determination, or can differ from the received CRC segment1012, which can be considered an “incorrectly” received CRC, i.e. a CRC“Fail” determination. An “incorrectly” received CRC “Fail” determinationcan indicate that one or more bit errors can exist in the received PCHbody 1010 and thus the received and decoded PCH message 1006 can beconsidered unreliable.

FIG. 10B illustrates a format 1020 for transmitting a layer 2 signalingF-CCCH message 1026 in an F-CCCH slot 1022 on the PCH/F-CCCH channel802. The layer 2 F-CCCH message 1026 resembles the layer 2 PCH message1006 having a length segment 1028, an F-CCCH body 1030 and a layer 2 CRCsegment 1032. The mobile station 302 can compare a calculated CRC to areceived layer 2 CRC segment 1032 for the layer 2 F-CCCH message 1026 inthe same manner as described for the PCH message 1006. The layer 2F-CCCH message 1026 can be segmented into a set of F-CCCH link accesscontrol (LAC) protocol data unit (PDU) fragments. A segmentationindicator (SI) 1024 can be appended to each F-CCCH LAC PDU fragment andseveral fragments can form a layer 1 F-CCCH frame. The layer 1 F-CCCHframe can be appended with an additional layer 1 CRC along with “k” tailbits for transmission in the F-CCCH slot 1022. Each F-CCCH frame canhave a duration of 5, 10 or 20 ms, and multiple F-CCCH frames can fitwithin an F-CCCH slot 1022 that can span 80 ms.

When the mobile station 302 operates in a slotted mode in the wirelessnetwork 300 with the QPCH 806 channel, the mobile station 302 candetermine use of signals received from one or more antennas andreceivers in the mobile station 302 based on observed decoding resultsfor the QPCH paging indicator bits 810/812. The mobile station 302 canselect from which multiple antennas to receive signals as well asdetermine whether to receive signals through both antennassimultaneously based on measured values for the QPCH PI1 and PI2 bits810/812. In addition, the mobile station 302 can use other measuredperformance indicators, such as measured received signal strength and/orreceived signal quality to influence the number and selection ofantennas and receivers to use as will be discussed further below.

FIG. 11 illustrates two different configurations 1100/1110 forconnections between the multiple antennas 508/510 and the multipletransceivers 504/506 for the mobile wireless device 102 (or the mobilestation 302). The DPDT switch 512 can connect the first antenna 508 andthe second antenna 510 in a “straight through” configuration 1000 to thefirst transceiver 504 and the second transceiver 506 respectively. Inaddition, the DPDT switch 512 can connect the first antenna 508 and thesecond antenna 510 in a “crossed” configuration 1110 to the secondtransceiver 506 and the first transceiver 504 respectively. When thefirst and second transceivers 504/506 can both support the samecommunications protocol, the mobile wireless device 102 can beconfigured to receive signals in either configuration. When operating ina single transceiver mode, such as by powering up the first transceiver504 and by powering down the second transceiver 506, the DPDT switch 512can be positioned to receive signals at the first transceiver 504 fromeither the first antenna 508 in the “straight through” configuration1000 or the second antenna 510 in the “crossed” configuration 1110. Oneconfiguration can be chosen over the other configuration based on aninstantaneous or an averaged performance measure, e.g. a signal qualitymeasure, a signal strength measure, a decoded bit quality measure orother similar performance measure. In one embodiment, decoded bit valuesreceived on the QPCH 806 channel can be used to determine which DPDTswitch 512 configuration 1100 or 1110 can be used for decoding the QPCH806 channel bit and also for receiving and decoding the associatedPCH/F-CCCH 802 channel

FIG. 12 illustrates a table 1200 of actions that can be taken by themobile wireless device 102 for a PCH/F-CCCH 804 time slot of thePCH/F-CCCH 802 channel 102 based on decoded values of one or twoassociated paging indicator bits 810/812 received on the QPCH 806channel The mobile wireless device 102 can awaken from a sleep state andread the paging indicator bits on the QPCH 806 channel in order todetermine whether to read a corresponding PCH/F-CCCH time slot 804 ofthe PCH/F-CCCH 802 channel When the first paging indicator bit PI1 810decodes to an “OFF” value (e.g. bit value=0), the mobile wireless device102 can determine that no signaling message exists on the PCH/F-CCCH 802channel to which the mobile wireless device 102 should listen. Thisconclusion can be made by the mobile wireless device 102 irrespective ofa value read on the paging indicator channel PI2 812. In an embodiment,when the first page indicator PI1 equals the “OFF” zero value, themobile wireless device 102 can avoid reading the second page indicatorPI2 to conserve additional battery power. The mobile wireless device 102can return to a sleep state to conserve battery power without monitoringthe second page indicator PI2 or the PCH/F-CCCH 802 channel. The mobilewireless device 102 can then re-awaken in the appropriate time slot ofthe next slot cycle to read the next received set of page indicator bitsPI1 810 and PI2 812 on the QPCH 806 channel When the first pageindicator PI1 810 equals an “ON” value (e.g. bit value=1), the mobilewireless device 102 can read the second page indicator PI2 812 inaddition to the first page indicator PI1 810 to determine a subsequentaction. When the first page indicator PI1 810 equals an “ON” value andthe second page indicator PI2 812 indicates an “OFF” value, the mobilewireless device 102 can conclude that no message exists on thePCH/F-CCCH 802 channel and sleep until the next slot cycle. Thus, whenreceiving an unequivocal “OFF” value in either the first page indicatorPI1 810 or in the second page indicator PI2 812, the mobile wirelessdevice 102 can return to sleep to conserve battery power and not readthe associated PCH/F-CCCH channel 802. When both the first pageindicator PI1 810 and the second PI2 812 page indicator decode to an“ON” value, the mobile wireless device 102 can receive and decode asignaling message (e.g. a paging message) on a corresponding PCH/F-CCCHtime slot 804 of the PCH/F-CCCH channel 802. The mobile wireless device102 can use the same initial antenna to read the PCH/F-CCCH channel 802as used to read the page indicators PI1/PI2 810/812 when both pageindicator bits are “ON”. When at least one of the page indicator bits isan equivocal “ERASURE” value, the mobile wireless device 102 can takeone of several different actions to resolve the uncertainty.

For a mobile wireless device 102 with a DPDT switch 512, the first pageindicator bit PI1 810 can be decoded using an initial antenna. Dependingon the initial configuration of the DPDT switch 512 the initial antennacan be either the first antenna 508 or the second antenna 510. In arepresentative embodiment, a default configuration for the DPDT switch512 can be the “straight through” configuration 1100, and the firstantenna 508 can be considered a primary antenna through which signalsare normally received, while the second antenna 510 can be considered asecondary antenna through which signals are received when warranted by ameasured signal strength/quality and/or based on page indicator bitdecode values. As indicated in the Table 1200 of FIG. 12, after decodingan “ON” bit value for both the first page indicator PI1 810 and thesecond page indicator PI2 812 received through the initial antenna, themobile wireless device 102 can decode the parallel subsequentaccompanying PCH/F-CCCH 802 channel also using the initial antenna.Similarly when the first page indicator PI1 810 decodes to an “ON” bitwhile the second page indicator PI2 812 decodes to an “Erasure” value,the mobile wireless device 102 can continue to use the initial antennato receive and decode the PCH/F-CCCH 802 channel as there is no strongindication (i.e. no “OFF” received) that no message exists on thePCH/F-CCCH 802 channel.

When the first page indicator bit 810 decodes to an “Erasure” value(i.e. neither clearly an “ON” or “OFF” value), the mobile wirelessdevice can use the DPDT switch 512 to receive signals selectively fromthe first or second antennas 508/510 when decoding the second pageindicator bit PI2 812 and the subsequent PCH/F-CCCH 802 channel. Inparticular, when the first page indicator bit PI1 810 received throughan initial antenna decodes to an “Erasure”, the mobile wireless device102 can toggle the DPDT switch 512 to read the second page indicator bitPI2 812 through an alternate antenna. For example, the initial antennacan be the first antenna 508 connected to the first transceiver 504 withthe DPDT switch in the “straight through” configuration 1100, anddecoding of the first page indicator bit PI1 810 as an “Erasure” canindicate poor signal quality received through the first antenna 508. Themobile wireless device 102 can change the configuration of the DPDTswitch 512 to the “crossed” configuration 1110 thereby connecting thesecond antenna 510 to the first transceiver 504. Signals receivedthrough the second antenna 510 can be of higher quality than signalsreceived through the first antenna 508. The mobile wireless device 102can then decode the second page indicator bit PI2 812 using the firsttransceiver 504 connected to the second antenna 510 as an alternateantenna.

When the mobile wireless device 102 decodes the second page indicatorbit PI2 812 as an “OFF” value indicating no signaling messageforthcoming, the mobile wireless device 102 can perform no decoding ofthe subsequent PCH/F-CCCH 802 channel When the mobile wireless device102 decodes the first page indicator bit PI1 810 as an “Erasure” valueand the second page indicator bit PI2 812 as an “ON” value, the mobilewireless device 102 can decode the PCH/F-CCCH 802 channel using thealternate antenna, i.e. the same antenna as used to decode the secondpage indicator bit PI2 812 rather than through the initial antenna usedto decode the first page indicator bit PI1 810. The unequivocal “ON”value received through the alternate antenna can indicate a betterreceived signal than the equivocal “Erasure” value received through theinitial antenna. When the mobile wireless device 102 decodes both thefirst page indicator bit PI1 810 as an “Erasure” through the initialantenna and the second page indicator bit PI2 812 also as an “Erasure”through the alternate antenna, the mobile wireless device 102 can togglethe DPDT switch 512 back to the initial antenna and subsequently decodethe PCH/F-CCCH 802 channel using signals received through the initialantenna. The pair of “Erasure” values for the page indicator bits PI1810 and PI2 812 can provide no definite indication of the presence orabsence of a signaling message on the PCH/F-CCCH 802 channel To avoidmissing a signaling message that can exist on the PCH/F-CCCH 802channel, the mobile wireless device 102 can attempt a decode of thePCH/F-CCCH 802 channel through the initial antenna (neither antennaproviding a distinct measureable advantage based on the received pageindicator bits PI1/PI2 810/812).

FIG. 13A illustrates a representative embodiment of a method 1300 toenable receive diversity in the mobile wireless device 102 during adiscontinuous reception (DRX) slot cycle based on measured values forquick paging channel page indicator bits 810/812 and decoding resultsfor the layer 2 CRC segment 1012 of the PCH message 1006. (The samemethod can apply to the discontinuous reception of F-CCCH messages 1026with layer 2 CRC segments 1032.) In step 1302, the mobile wirelessdevice 102 can awaken and re-acquire the wireless network 100 using aninitial antenna. In a representative embodiment, the initial antenna canbe a primary “preferred” antenna, while in another representativeembodiment, the initial antenna can be a most recently used antenna. Instep 1304, the mobile wireless device can compare a measured downlinksignal quality to a pre-determined threshold. In a representativeembodiment, the downlink signal quality can be measured using a receiveddownlink signal strength, such as a received signal strength indicator(RSSI) or a received signal code power (RSCP), or using a receiveddownlink signal quality, such as a measured signal (code power) tonoise/interference ratio (EcIo) or signal to noise ratio (SNR). Thedownlink signal quality measurement can include filtering measuredvalues to smooth instantaneous variation in measured values that canoccur over short time periods. Thus, the downlink signal quality can bea “filtered” measured downlink signal quality. When the downlink signalquality exceeds the pre-determined threshold, the mobile wireless device102 can subsequently decode page indicators 810/812 received on a quickpaging channel 806 in step 1306. When the downlink signal quality doesnot exceed the pre-determined threshold, the mobile wireless device 102can conclude that the page indicators can be unreliable (due to the poorreceived downlink signal quality) and can instead directly decode thepaging channel using an initial antenna in step 1312 irrespective ofwhat the page indicators can indicate.

Following decoding of the quick paging channel 806 page indicators810/812 in step 1306, the mobile wireless device 102 can determine instep 1308 if either the first page indicator 810 or the second pageindicator 812 decodes to an “OFF” value. When either the first pageindicator 810 or the second page indicator 812 decodes to an “OFF” valueas determined in step 1308, the mobile wireless device 102 can return tosleep in step 1322. When neither the first page indicator 810 nor thesecond page indicator 812 decodes to an “OFF” value, the mobile wirelessdevice can subsequently determine with which antenna to decode thepaging channel 802 based on the value decoded on the first pageindicator 810. When the first page indicator 810 does not decode to an“erasure” value, the mobile wireless device 102 can decode the paging(PCH/F-CCCH) channel 802 in step 1314 using the initial antenna. Whenthe first page indicator 810 decodes to an “erasure” value, then themobile wireless device 102 can decode the paging channel 802 in step1312 using an alternate antenna.

In step 1316, the mobile wireless device 102 can determine if a CRCsegment 1012 of a signaling (paging) message 1006 received on the pagingchannel 802 correctly decodes as a “Pass”. When the CRC segment 1012 ofthe signaling message 1006 decodes to a “Pass”, the mobile wirelessdevice 102 can determine in step 1318 if at least one CRC segment 1012of a previously decoded signaling message 1006 received on the pagingchannel 802 during the same wake cycle decodes to a CRC “Fail”. When themobile wireless device 102 determines at least one CRC “Fail” is decodedin the current wake cycle and also that one CRC “Pass” is decoded in thecurrent wake cycle, the mobile wireless device 102 can enable fullreceive diversity in step 1320. The decoded CRC “Fail” can indicate apoor receive signal quality condition that can warrant improving signalreception by using receive diversity through multiple antennas. Fullreceive diversity can include connecting multiple antennas 508/510 tomultiple transceivers 504/506 in the mobile wireless device 102 topermit decoding of signals received through more than one antenna508/510 during the next wake cycle. In step 1320, during the next wakecycle, the mobile wireless device 102 can also ignore the quick pagingchannel 806 (QPCH) and directly decoding the paging channel 802 usingfull diversity without decoding page indicator bits 810/812 on thepaging channel 802. When the mobile wireless device 102 decodes a CRC“Pass” in step 1316 and does not decode a CRC “Fail” in the current wakecycle in step 1318, the mobile wireless device 102 can return to a sleepstate in step 1322 without enabling receive diversity. The mobilewireless device 102 can then repeat the method from step 1302 in a wakeportion of a subsequent DRX cycle.

The mobile wireless device 102 can decode the paging channel PCH/F-CCCH802 in steps 1312 and 1314 and continuously look for a receivedsignaling message that decodes with a “Pass” CRC. When the mobilewireless device 102 does not decode a CRC “Pass”, in step 1324, themobile wireless device 102 can determine if a persistent CRC “Fail”condition exists or whether no CRC can be detected (CRC “Absence”). In arepresentative embodiment, persistent CRC “Failure” can be determinedwhen decoding messages on the paging channel 802 that continuouslyresult in CRC decoding failures for a pre-determined period of time or apre-determined number of consecutive CRC decoding failures. CRC“absence” can occur when no CRC can be detected on the paging channel802 by the mobile wireless device 102 for a pre-determined period oftime. When the mobile wireless device 102 detects persistent CRC failureof a CRC absence in step 1324, the mobile wireless device 102 in step1326 can enable full receive diversity and continue decoding of thepaging channel 802 during the current wake cycle as shown in FIG. 13B byconnecting through the circle labeled “FD”. Decoding of the pagingchannel 802 in steps 1312 and 1314 of FIG. 13A can use a single antenna(e.g. 508 or 510) initially, while decoding of the paging channel 802 instep 1326 of FIG. 13B can use multiple antennas (e.g. 508 and 510)simultaneously to improve signal detection when receive signalconditions can be poor. When the mobile wireless device 102 does notdecode a CRC “Pass” in step 1316 and subsequently does not detectpersistent CRC failure or absence in step 1324, the mobile wirelessdevice can continue to decode the paging channel 802 using a singleantenna (either the initial antenna or the alternate antenna as chosenwhen entering step 1316) and return to check for a successful CRC “Pass”decode in step 1316.

In FIG. 13B, the mobile wireless device 102 can continue decoding thepaging channel step 1326 during the current wake cycle using multipleantennas (e.g. 508 and 510) simultaneously. This decoding with multipleantennas can be referred to as full antenna diversity. Using fullantenna diversity can improve received signal quality and therefore canimprove the probability of error free decoding of the paging channelmessages. When a CRC is decoded, the mobile wireless device in step 1330can determine if a CRC “Pass” has been decoded during the current wakecycle and also been decoded for a number of previous consecutive wakecycles. When multiple consecutive wake cycles decode with a correct CRC“Pass”, the mobile wireless device can revert to using a single antennaduring the next wake cycle as indicated in step 1332 and subsequentlysleep in step 1336. When an incorrect CRC “Fail” is decoded in thecurrent wake cycle or when a pre-determined number of consecutive wakecycles have not decoded a correct CRC “Pass”, then the mobile wirelessdevice 102 can continue to use multiple antennas (i.e. full antennadiversity) in the next wake cycle as indicated in step 1334 and returnto sleep in step 1336. As indicated in FIG. 13A, full antenna diversitycan be enabled following at least one CRC failure during a wake cycle(even when at least one CRC pass can also occur during the same wakecycle). Full antenna diversity can also be enabled when persistent CRCfailure or CRC absence occurs. The mobile wireless device 102 can returnto using single antenna for decoding after a repeated CRC pass occursfor a pre-determined number of consecutive wake cycles.

The method 1300 outlined in FIGS. 13A and 13B provides several distinctresults that balance performance with power consumption in selectivelyenabling receive diversity. Single bit page indicators PI1/PI2 810/812can be read when received downlink signal quality is good and ignoredwhen received downlink signal quality is poor. Thus power can be notwasted to read unreliable poor quality page indicators. An “OFF”detected on the first page indicator PI1 810 or on the second pageindicator PI2 812 can return the mobile wireless device 102 to a sleepstate to conserve power and not read the accompanying paging channel 802during the DRX cycle. An erasure detected on the first page indicatorPI1 810 can result in switching between an initial antenna and analternate antenna, thereby decoding through an alternate path that canhave superior signal quality while still using only one antenna and onetransceiver (which can consume less power than multiple antennas andmultiple receivers). The paging channel 802 can be decoded using signalsreceived through a single antenna, and decoding of the page indicators810/812 can provide an indication of signal quality received through thesingle antenna and thus can determine which single antenna to use whendecoding the paging channel 802. When persistently unable to detect a“Pass” CRC on a paging channel 802 through a single antenna, the mobilewireless device 102 can enable receive diversity to receive signalsthrough multiple antennas and continuing decoding of the paging channel802 during the current wake portion of the DRX cycle. While consumingadditional power, the use of multiple antennas can provide more reliablereception of the paging channel 802 during poor signal conditions. Whendecoding at least one “Fail” CRC and one “Pass” CRC using a singleantenna in the wake portion of a DRX cycle, the mobile wireless device102 can enable receive diversity during the next wake portion of asubsequent DRX cycle to improve detection and decoding of the pagingchannel 802. The quick paging channel 806 can be ignored when usingreceive diversity and the paging channel 802 can be read directly, asreceive diversity can be enabled specifically when poor receive signalquality can exist, under which conditions single bit page indicators810/812 can be considered less reliable.

FIGS. 14 to 19 outline a second detailed method 1400 to 1900 to adaptreceive diversity in the mobile wireless device 102 during discontinuousreception. The steps illustrated in FIGS. 14 to 19 are interconnectedthrough the circle entry and exit points labeled with letters A throughH. The mobile wireless device 102 can cycle between a sleep state and awake state in the discontinuous reception (DRX) mode of operation. Thewake portion can include monitoring a paging channel 802 that cancontain paging messages 1006 and a quick paging channel 806 that canprovide paging indicators 810/812. The mobile wireless device 102 can bein one of five different states S1 to S5 during the sleep portion of aDRX cycle. When the mobile wireless device 102 awakens from sleep, themobile wireless device can be in one of the five different states S1 toS5, and awakening in each state can result in a different sequence ofsteps as outlined in FIGS. 14 to 18 for states S1 to S5 respectively.

From state S1 in FIG. 14, the mobile wireless device 102 can decode thepaging channel 802 directly using a primary antenna without reading pageindicator bits 810/812 on the quick paging channel 806. From state S2 inFIG. 15, the mobile wireless device 102 can decode page indicator bits810/812 on the quick paging channel 806 using the primary antenna todetermine whether to decode the paging channel 802 (and to determinewhich antenna to use for the subsequent decoding of the paging channel802). State S3 in FIG. 16 can be considered similar to state S2 in FIG.15 except the mobile wireless device 102 can use a secondary antenna inplace of the primary antenna initially. In particular, from state S3 inFIG. 16, the mobile wireless device 102 can decode page indicator bits810/812 on the quick paging channel 806 using the secondary antenna todetermine whether to decode the paging channel 802 (and to determinewhich antenna to use for the subsequent decoding of the paging channel802). State S4 in FIG. 17 can be considered similar to state S1 in FIG.14 except that the mobile wireless device 102 can use a secondaryantenna in place of the primary antenna initially. From state S4 in FIG.17, the mobile wireless device 102 can decode the paging channel 802directly using a secondary antenna without reading page indicator bits810/812 on the quick paging channel 806. From state S5 in FIG. 18, themobile wireless device can decode the paging channel 802 directly usingfull receive diversity through both the primary and secondary antennastogether.

Returning to FIG. 14, in step 1402, the mobile wireless device 102 canawaken in state S1, and in step 1404, the mobile wireless device 102 canre-acquire the wireless network 100 using a primary antenna. The primaryantenna can be a default antenna connected to a default receiver in themobile wireless device 102. Re-acquisition can include detecting signalsand aligning synchronization timing with a previously detected cell inthe wireless network 100. In step 1406, the mobile wireless device 102can decode the paging channel 802 directly using signals receivedthrough the primary antenna. In step 1408, the mobile wireless device102 can determine if a paging channel message has been received on thepaging channel 802 and decoded with a correct “Pass” CRC. When no pagingchannel message is received with a correct “Pass” CRC, the mobilewireless device can determine in step 1424 if a paging channel messagehas been received and decoded with an incorrect “Fail” CRC. If no pagingchannel message has been received with a correct “Pass” CRC or anincorrect “Fail” CRC, the mobile wireless device in step 1422 candetermine if no paging channel message has been received with a correct“Pass” CRC for a predetermined period of time of T1 seconds. Thedetermination in step 1422 of a continuous time period of T1 secondswith no “Pass” CRC can be implemented with a countdown timer. Thecountdown timer can be initialized to T1 seconds when decoding of thepaging channel 802 in step 1406 begins, and the countdown timer can bereset to T1 seconds when a correct “Pass” CRC is received as determinedin step 1408. When T1 seconds of decoding the paging channel 802 resultsin no CRC Pass (and no CRC Fail), the mobile wireless device 102 cantransition to step 1428 and enable full receiver diversity. With fullreceive diversity enabled, the mobile wireless device 102 can receivesignals through both the primary antenna and the secondary antennas. Ina representative embodiment, the primary antenna can be connected to onetransceiver and the secondary antenna can be connected to a secondtransceiver through a dual pole dual throw switch 512 in the mobilewireless device 102. With full receive diversity enabled, the mobilewireless device 102 can continue decoding the paging channel 802 asindicated in FIG. 14 by transitioning through the circle “C” to step1806 shown in FIG. 18.

The cycle of steps 1406 to 1408 to 1424 to 1422 and back to 1406 in FIG.14 can provide a continuous decoding of the paging channel 802 by themobile wireless device 102 using the primary antenna to search for apaging channel message 1006 with a “Pass” CRC. After receiving a pagingchannel message 1006 with a CRC Fail as determined in step 1424, themobile wireless device 102 can determine if a number (X1) of consecutivepaging messages 1006 have been received with CRC Fail. When X1consecutive CRC failures have occurred, the mobile wireless device 102can transition to full received diversity in step 1428 to continuedecoding of the paging channel 802 using signals received from multipleantennas. When X1 consecutive CRC failures have not yet occurred asdetermined in step 1426, the mobile wireless device 102 can transitionto step 1422 to determine if no paging channel messages 1006 have beenreceived within a predetermined T1 seconds of decoding the pagingchannel 802. The steps 1426 and 1428 can provide a determination of poorsignal reception when multiple consecutive “incorrect” CRC are receivedor when no “correct” CRC is received within a pre-determined period oftime. Decoding with multiple antennas, i.e. with full receive diversity,can improve signal reception and thus improve decoding of the pagingchannel 802.

When the mobile wireless device 102 receives a paging channel message1006 with a “correct” CRC Pass and no additional paging channel messages1006 are expected in the current wake cycle (i.e. mobile wireless device102 does not need to receive until the next wake cycle), the mobilewireless device 102 can determine in step 1410 if one or more previouspaging channel messages 1006 was decoded with an “incorrect” CRC Failduring the current wake portion of the DRX cycle. When receiving atleast one “incorrect” CRC Fail as determined in step 1410 and a“correct” CRC Pass as determined in step 1408 during decoding of thepaging channel 802 in a single wake portion of the current DRX cycle,the mobile wireless device 102 can transition to step 1418 andre-initialize a discontinuous reception (DRX) counter followed byreturning to sleep in step 1420 in state S5. When the mobile wirelessdevice 102 wakens from state S5 for a next wake portion of a DRX cycleto decode the paging channel, the mobile wireless device will executestep 1802 shown in FIG. 18. The reception of a paging channel message1006 with an incorrect CRC Fail can indicate a lower level of signalquality. As such, the mobile wireless device 102 can awaken in the nextDRX cycle using receive diversity to improve signal reception.

After receiving a paging channel message 1006 with a correct CRC Pass instep 1408 and when not receiving a paging channel message 1006 with anincorrect CRC Fail (in steps 1424 or 1420), the mobile wireless device102 can compare a receive signal quality to a pre-determined firstthreshold in step 1412. The receive signal quality can be a measure ofsignal quality such as a receive signal code power to noise/interferenceration (EcIo) and can be a filtered measure that averages measurementsof receive signal quality over a period of time. When the receive signalquality does not exceed the pre-determined first threshold in step 1412,the mobile wireless device 102 can return to sleep in state S1 in step1414. When the mobile wireless device 102 re-awakens in state S1 duringthe next DRX cycle, the mobile wireless device 102 can repeat the methodsteps outlined in FIG. 14 from the initial step 1402. A lower level ofreceive signal quality can indicate that decoding the paging channel 802directly without decoding the quick paging channel indicator bits810/812 can be preferred. When the receive signal quality exceeds thepre-determined first threshold in step 1412, the mobile wireless device102 can sleep in state S2 in step 1416. Awakening from sleep in a wakeportion of a subsequent DRX cycle, the mobile wireless device 102 cancontinue as shown next in FIG. 15.

FIG. 15 illustrates a series of steps 1500 that the mobile wirelessdevice 102 can take when awakening from sleep in state S2 in step 1502.The mobile wireless device 102 can re-acquire the wireless network 100using signals received through the primary antenna in step 1504. Themobile wireless device 102 can then receive signals on a quick pagingchannel 806, and in particular decode a first page indicator 810 usingsignals received through the primary antenna in step 1506. The receivedfirst page indicator 810 can be a single bit that can be interpreted asone of three possible values, a “zero” value, a “one” value and an“erasure” value. (Note that the “zero” value for an “OFF” indication ofno paging message 1006 and a “one” value for an “ON” indication of apaging message 1006 is arbitrary and can alternatively be swapped, i.e.“OFF” could be a “one” value and “ON” could be a “zero” value.) Themobile wireless device 102 can determine the value of the received firstpage indicator 810 in steps 1508, 1510 and 1520. When the first pageindicator bit 810 decodes to a zero value in step 1508, which canindicate no paging message 1006 for the mobile wireless device 102 onthe parallel paging channel 802, the mobile wireless device 102 can exitdecoding of the quick paging channel 806 and can directly determine anext sleep state based on the receive signal quality by re-entering step1412 in FIG. 12 as indicated by the circle “B”. When the first pageindicator 810 decodes to an “erasure” in step 1520, the mobile wirelessdevice 102 can determine that the current antenna in use (the primaryantenna) can be unreliable and can toggle the DPDT switch in step 1522to route signals from the secondary antenna to the receiver. The mobilewireless device 102 can then continue decoding of the quick pagingchannel 806 using the secondary antenna by entering step 1612 asindicated by the circle “E” in FIG. 16.

When the first page indicator 810 decodes to a “one” value in step 1510,the mobile wireless device 102 can optionally sleep and subsequentlyreacquire the wireless network 100 on the primary antenna in step 1512and decode a received second page indicator 812 through the primaryantenna in step 1514. As with the first page indicator bit 810, thereceived second page indicator 812 can be a single bit that can beinterpreted as a “zero”, a “one” or an “erasure”. When the second pageindicator 812 decodes to a “zero” in step 1516, the mobile wirelessdevice 102 can exit decoding of the quick paging channel 806 and candirectly determine a next sleep state based on the receive signalquality by re-entering step 1412 in FIG. 12 as indicated by the circle“B”. Thus when a single page indicator bit 810 is unequivocally receivedas a “zero” value indicating that no paging message 1006 is intended forthe mobile wireless device 102 on the paging channel 802, the mobilewireless device 102 can return to a sleep state. The quality of thereceived signal quality can be used to determine in which state to sleepand subsequently re-awaken. Page indicators 801/812 on the quick pagingchannel 806 can be considered more reliable and therefore merit decodingwhen signal quality is high and less reliable and therefore warrant notdecoding when signal quality is low.

When the second page indicator 812 decodes to a “one” value in step1518, the mobile wireless device 102 can transition as indicated by thecircle “A” to step 1404 in FIG. 14 in order to decode the paging channel802 using the primary antenna as previously described above. When thesecond page indicator 812 decodes to an “erasure” value in step 1524 andwhen the first page indicator 810 decodes to an “erasure” value in step1526, the mobile wireless device 102 can toggle the DPDT switch in step1528 and transition through the circle “F” to step to step 1704 in FIG.17 to decode the paging channel 802 using the secondary antenna. Whenthe first page indicator 810 does not decode to an “erasure” in step1526, the mobile wireless device 102 can transition through the circle“A” to step 1404 in FIG. 14 to decode the paging channel 802 using theprimary antenna. FIG. 15 illustrates the mobile wireless device 102using the page indicator bit 810/812 decoded values to determine whetherto decode the paging channel 802 and which antenna to use for thedecoding of the paging channel 802. In FIG. 15, the mobile wirelessdevice 102 starts decoding the page indicators 810/812 using the primaryantenna, while in FIG. 16, the mobile wireless device 102 startsdecoding the page indicators 810/812 using the secondary antenna.

FIG. 16 illustrates a series of steps that the mobile wireless device102 can take when awakening from sleep in state S3 in step 1602. Themobile wireless device 102 can reacquire the wireless network 100 instep 1604 using signals received through the secondary antenna. Themobile wireless device 102 can then decode the first page indicator 810received through the secondary antenna in step 1606 and subsequently candetermine its value. When the first page indicator 810 decodes to a“zero” value in step 1608, the mobile wireless device 102 can concludeno signaling (paging) message 1006 exists on the paging channel 802 andcan transition through the circle “G” to return to a sleep state basedon a received signal quality starting in step 1712 of FIG. 17. Thereceived signal quality can be compared to a pre-determined firstthreshold as indicated in step 1712. When the received signal qualityexceeds the first threshold in step 1712, the mobile wireless device 102can return to sleep in state S3 in step 1716. When the received signalquality does not exceed the first threshold in step 1712, the mobilewireless device 102 can sleep in state S4 in step 1714.

Returning to FIG. 16, when the received first page indicator 810 decodesto a “one” value in step 1610, the mobile wireless device 102 canoptionally sleep (not shown) and then can re-acquire the wirelessnetwork 100 using signals received through the secondary antenna in step1612. The mobile wireless device 102 can subsequently decode a secondpage indicator 812 received through the secondary antenna in step 1614and determine its value. When the received second page indicator 812decodes to a “zero” value in step 1616, the mobile wireless device 102can conclude there is no forthcoming paging channel message 1006. Themobile wireless device 102 can transition through the circle “G” toreturn to sleep based on the received signal quality as determined instep 1712 of FIG. 17.

When the received second page indicator 812 decodes instead to a “one”value in step 1618, the mobile wireless device 102 can decode the pagingchannel 802 based on signals received through the secondary antenna bytransitioning through the circle “F” to step 1704 in FIG. 17. Otherwise,when the received second page indicator 812 decodes to an “erasure”value in step 1624 and the received first page indicator 810 alsodecodes to an “erasure” in step 1626, the mobile wireless device 102 cantoggle the antenna switch back to the primary antenna from the secondaryantenna in step 1628 and transition through the circle “A” to step 1404of FIG. 14 to decode the paging channel 802 using the primary antenna.When the received second page indicator 812 decodes to an “erasure”value in step 1624 and the received first page indicator 810 does notdecode to an “erasure” in step 1626, the mobile wireless device 102 cantransition through circle “F” to decode the paging channel 802 usingsignals received through the secondary antenna starting in step 1704 ofFIG. 17.

When the received first page indicator 810 does not decode to a “zero”in step 1608 and does not decode to a “one” in step 1610, the mobilewireless device 102 can conclude the first page indicator 810 decodes toan “erasure” in step 1620. Receipt of the first page indicator 810 withan “erasure” can indicate poor signal quality received through thesecondary antenna. In response, the mobile wireless device 102 cantoggle the DPDT switch in step 1622 from the secondary antenna to theprimary antenna and transition through circle “D” to step 1512 in FIG.15 to decode the second page indicator 812 using the primary antenna. An“erasure” on the first page indicator 810 can cause the DPDT switch totoggle once to attempt decoding of the second page indicator 812 on adifferent antenna from the antenna used for decoding the first pageindicator 810. A second “erasure” on the second page indicator 810 cancause the DPDT switch to toggle back again to the primary antenna beforedecoding the paging channel 802 or returning to sleep. An “erasure” onthe second page indicator 812 only without an “erasure” on the firstpage indicator 810 can result in no change in the DPDT switch with thesame antenna used for decoding both page indicators 810/812 and theassociated paging channel 802.

FIG. 17 illustrates a series of steps 1700 similar to those illustratedin FIG. 14 except the mobile wireless device 102 awakens in state S4 instep 1702 and re-acquires the wireless network 100 on the secondaryantenna in step 1704. (FIG. 14 starts with the mobile wireless device102 using the primary antenna first.) In step 1706, the mobile wirelessdevice 102 can begin decoding the paging channel 802 using signalsreceived through the secondary antenna. The mobile wireless device 102can continue to decoding the paging channel 802 checking for a pagingchannel message 1006 and determining a CRC “Pass” or “Fail” condition insteps 1708 and 1724. When the mobile wireless device 102 receives apaging channel message 1006 that decodes with a correct “Pass” CRC andconfirms that there are no more paging channel messages 1006 expectedduring the current wake cycle, the mobile wireless device 102 can stopdecoding the paging channel 802 and return to a sleep state. The sleepstate to which the mobile wireless device 102 returns can depend onwhether a paging message 1006 was received in the current wake cyclewith an incorrect “Fail” CRC as determined in step 1710. If the mobilewireless device 102 receives both a correct “Pass” CRC and at least oneincorrect “Fail” CRC during the same wake portion of the DRX cycle whendecoding the paging channel 802, the mobile wireless device 102 canre-initialize a DRX counter in step 1718 and sleep in state S5 in step1720. When awakening from state S5, the mobile wireless device 102 canuse full receive diversity (i.e. signals received from multipleantennas) to decode the paging channel 802 to improve signal detectionand decoding. When the mobile wireless device 102 receives a pagingchannel message 1006 with a correct “Pass” CRC in step 1708 and does notreceive a paging channel message 1006 with an incorrect “Fail” CRC inthe same wake portion of the DRX cycle, the mobile wireless device 102can return to a sleep state based on a receive signal qualitydetermination in step 1712. When the receive signal quality exceeds thefirst pre-determined threshold in step 1712, the mobile wireless device102 can return to sleep in state S3, out of which the mobile wirelessdevice 102 can decode paging indicators 810/812 on the quick pagingchannel 806. When the receive signal quality does not exceed the firstpre-determined threshold in step 1712, the mobile wireless device 102can return to sleep in state S4, from which the mobile wireless device102 can decode the paging channel 802 directly and can ignore the quickpaging channel 806.

The mobile wireless device 102 can cycle through steps 1706, 1708, 1724and 1722 when decoding the paging channel 802 on the secondary antennain search of a paging channel message 1006 received with a correct“Pass” CRC. A paging channel decoding countdown timer can be started ata predetermined value of T1 seconds when beginning the decoding of thepaging channel 802 on the secondary antenna in step 1706. The pagingchannel decoding countdown timer can be reset to the predetermined valueof T1 seconds whenever a correct “Pass” CRC for a paging channel message1006 is received. When no paging channel message 1006 is received by themobile wireless device 102 with a “Pass” CRC for a period of T1 secondsof decoding the paging channel 802 as determined in step 1722, themobile wireless device 102 can enable full receive diversity to usemultiple antennas in step 1728. The mobile wireless device 102 cansubsequently continue to decode the paging channel 802 with full receivediversity by transitioning through circle “C” to step 1806 in FIG. 18.The mobile wireless device 102 can also keep track of the number ofpaging channel messages 1006 received during a wake portion of a currentDRX cycle that decode with an incorrect “Fail” CRC. When the mobilewireless device 102 receives a number (X1) of consecutive pagingmessages 1006 with an incorrect “Fail” CRC as determined in step 1726,the mobile wireless device 102 can enable full diversity in step 1728and continue decoding with full diversity in step 1806 of FIG. 18. Afterdecoding the paging channel 802 continuously without detecting a CRC“Pass” or detecting multiple consecutive CRC “Fail”, the mobile wirelessdevice 102 can conclude that signal quality received through the singlesecondary antenna can be insufficient. By enabling full receivediversity with multiple antennas in step 1728, the mobile wirelessdevice 102 can improve the receive signal quality and thus improvedetection and decoding of paging channel messages 1006 received on thepaging channel 802.

FIG. 18 illustrates a series of steps 1800 that the mobile wirelessdevice 102 can perform to decode the paging channel 802 with fullreceive diversity through multiple antennas. In step 1802, the mobilewireless device 102 can awaken in state S5, and in step 1804, the mobilewireless device 102 can re-acquire the wireless network 100 with fulldiversity using signals received through both the primary antenna andthe secondary antennas. In step 1806, the mobile wireless device 102 candecode the paging channel 802 with full receive diversity continuouslysearching for paging channel messages 1006 with a correct “Pass” CRC.When the mobile wireless device 102 receives a paging channel message1006 with a correct “Pass” CRC as determined in step 1808 and when themobile wireless device 102 confirms that there is no additional pagingchannel messages 1006 expected in the current wake cycle, the mobilewireless device 102 can decrement a DRX counter in step 1810. The DRXcounter can have been re-initialized in step 1418/1718/1826 beforereturning to sleep 1420/1720/1828 in state S5 from which the mobilewireless device 102 awakens in step 1802. The DRX counter can count downa number of DRX cycles in which the mobile wireless device 102successfully decodes a paging channel message 1006 with a correct “Pass”CRC while using full receive diversity. The DRX counter can provide aform of hysteresis, in which the mobile wireless device 102 can continueto use full receive diversity with multiple antennas to decode thepaging channel 802 for a pre-determined number of consecutive wakecycles with successful “Pass” CRC and without an incorrect “Fail” CRCbefore returning to using only a single antenna. When the DRX counterdoes not equal zero as determined in step 1812, the mobile wirelessdevice 102 can sleep in state S5 as indicated in step 1828.

When the DRX counter does equal zero as determined in step 1812, themobile wireless device 102 can use both a receive signal quality and areceive signal strength to determine in which state to sleep beforere-awakening in a subsequent DRX cycle. In a representative embodiment,the receive signal quality can be a measure of received signal codepower divided by the total receive noise and interference level (EcIo).The receive signal strength can be a receive signal code power (RSCP) ormeasured received pilot strength or another similar measure of receivesignal power monitored by the mobile wireless device 102. Both thereceive signal strength and the receive signal quality can be filteredover time to smooth out instantaneous measurement variation. When thereceive signal quality exceeds a pre-determined first threshold in step1814, the mobile wireless device 102 can sleep in a state out of which asingle antenna can be subsequently used for monitoring page indicators810/812 on the quick paging channel 806. The mobile wireless device 102can select between the primary antenna and the secondary antenna bycomparing a signal strength delta (difference) between a signal strengthmeasured on the secondary antenna and a signal strength measured on theprimary antenna. The signal strength delta can be compared to apre-determined second threshold in step 1816. When the signal strengthdelta exceeds the pre-determined second threshold in step 1816, themobile wireless device 102 can sleep in state S3 as shown in step 1818.(From state S3, the mobile wireless device 102 can awaken to use signalsreceived on the secondary antenna as shown in FIG. 16.) When the signalstrength delta does not exceed the pre-determined second threshold instep 1816, the mobile wireless device 102 can sleep in state S2 asindicated in step 1820. (From state S2, the mobile wireless device 102can awaken to use signals received on the primary antenna as shown inFIG. 15.)

When the receive signal quality does not exceed the pre-determined firstthreshold in step 1814, the mobile wireless device 102 can sleep in astate out of which a single antenna can be subsequently used formonitoring the paging channel 802 directly and can skip over monitoringthe paging indicators 810/812 on the quick paging channel 806. Thecalculated signal strength delta can be used to select in which state tosleep and from which state to awaken in the next cycle. When the signalstrength delta exceeds the pre-determined second threshold in step 1830,the mobile wireless device 102 can sleep in state S4 as shown in step1832. (From state S4, the mobile wireless device 102 can awaken to usesignals received on the secondary antenna as shown in FIG. 17.) When thesignal strength delta does not exceed the pre-determined secondthreshold in step 1830, the mobile wireless device 102 can sleep instate S1 as indicated in step 1834. (From state S1, the mobile wirelessdevice 102 can awaken to use signals received on the primary antenna asshown in FIG. 14.) The measured (and filtered) receive signal qualitycan be thus used to select whether to decode page indicators 810/812 inthe wake portion of the next DRX cycle or to decode the paging channel802 directly. The measured (and filtered) receive signal strength delta(a measure of a difference in signal strengths received through the twoantennas) can be used to select which of the two antennas to decode inthe next DRX cycle.

When the mobile wireless device 102 receives a paging channel message1006 that decodes with an incorrect CRC “Fail” in step 1824, the DRXcounter can be re-initialized in step 1826, and the mobile wirelessdevice 102 can return to sleep in state S5 as indicated in step 1828.The DRX counter can be re-initialized each time an incorrect CRC “Fail”is detected while decoding the paging channel 802 with full receivediversity to keep the mobile wireless device 102 in state S5 untilreceive signal quality improves (as measured by a number of wake cycleswith successful CRC “Pass” detections.) When continuously decoding thepaging channel 802 with full diversity, a decoding timer can be startedwhen entering step 1806. The decoding timer can run while the mobilewireless device 102 traverses the cycle of steps 106 to 1808 to 1824 to1822 and back to 1806 again. The decoding timer can be reset whenever acorrect CRC “Pass” is detected. When the decoding timer expires in step1822, the mobile wireless device 102 is unable to receive a pagingchannel message 1006 with any detected CRC for a continuouspre-determined period of time, even when using full receive diversitywith signals received through both the primary and secondary antennas.In this circumstance, the mobile wireless device 102 can transition toperform a system determination through circle “H” to step 1904 in FIG.19.

The method steps outlined in FIGS. 13, 14, 17 and 18 include checking alayer 2 CRC segment 1012 received as part of a layer 2 paging channelmessage 1006. The same steps can also apply to checking a layer 2 CRCsegment 1032 received as part of a layer 2 control channel message 1026or more generally to detecting transmission errors in received signalingmessages that include layer 2 CRC segments. In addition to errordetection for layer 2 messages, a mobile wireless device 102 can use aprotocol that includes error detection for layer 1 such as the layer 1CRC segment attached to an F-CCCH frame shown in FIG. 10B. A singlelayer 2 F-CCCH message 1026 can include one or more F-CCCH frames, andeach F-CCCH frame can include a separate layer 1 CRC. The method stepsoutlined in FIGS. 13, 14, 17 and 18 can be extended to include checkingfor CRC “Pass” or CRC “Fail” using the layer 1 CRC rather than (or inaddition to) the layer 2 CRC segment 1032. In the mobile wireless device102, layer 1 processing of layer 1 frames can occur before segmentationand reassembly (SAR) of the layer 2 segment and thus detection of errorscan occur earlier and more frequently (as multiple layer 1 CRC segmentscan be included in a single layer 2 F-CCCH message 1026). When usinglayer 1 CRC to detect CRC “Fail” conditions, the number of consecutiveCRC failures in step 1426 of FIG. 14 and in step 1726 in FIG. 17 candiffer from the number of consecutive CRC failures used with layer 2 CRCfailures. Similarly, the amount of time used to determine an absence ofCRC passing in step 1422 of FIG. 14 and in step 1722 in FIG. 17 can bethe same or can differ when using layer 1 CRC versus layer 2 CRC.

FIG. 19 illustrates a series of steps 1900 that the mobile wirelessdevice 102 can undertaken when unable to re-acquire the paging channel802 or following a paging channel 802 decoding timer expiration. EachDRX cycle, the mobile wireless device 102 can re-awaken from one of thefive sleep states described above and can re-acquire the wirelessnetwork 100 using one antenna or multiple antennas to decode the pagingchannel 802 (and/or the quick paging channel 806). The mobile wirelessdevice 102 can also optionally sleep between reading two distinct pagingindicators 810/812 on the quick paging channel 806 during a single DRXcycle. When the mobile wireless device 102 is unable to re-acquire thewireless network 100 to decode the paging channel 802 in step 1902, themobile wireless device 102 can perform a limited scan for radio sectors104 (cells) in the wireless network 100 in step 1904 using signalsreceived through the secondary antenna. In a representative embodiment,the limited scan can include searching for one or two radio sectors 104in a list of most recently used radio sectors 104 stored in the mobilewireless device 102. When the mobile wireless device 102 locates a radiosector 104 in step 1906, the mobile wireless device 102 can compare areceived signal quality to a pre-determined first threshold in step 1914to determine in which state to sleep. The received signal quality can bea filtered measured signal quality such as a ratio of received signalcode power to noise/interference (EcIo). When the received signalquality exceeds the first threshold as determined in step 1914, themobile wireless device 102 can sleep in state S3 in step 1916. Fromstate S3, the mobile wireless device 102 can later awaken to decode pageindicators 810/812 on the quick paging channel 806 using signalsreceived through the secondary antenna as shown in FIG. 16. When thereceived signal quality does not exceed the first threshold asdetermined in step 1914, the mobile wireless device 102 can sleep instate S4 in step 1916. From state S4, the mobile wireless device 102 canre-awaken to decode the paging channel 802 directly using signalsreceived through the secondary antenna as shown in FIG. 17.

When the limited scan for radio sectors 104 of the wireless network 100using signals received through the secondary antenna fails in step 1906,the mobile wireless device 102 can perform a full scan for radio sectors104 of the wireless network 100 using signals received through theprimary antenna in step 1908. In a representative embodiment, the fullscan for radio sectors 104 can include those radio sectors 104 searchedfor in step 1904 during the limited scan with signals received throughthe secondary antenna and additional radio sectors 104 stored in one ormore lists in the mobile wireless device 102. When no radio sector 104can be located using the primary antenna in step 1910, the mobilewireless device 102 can enter an “out of service” recovery process instep 1912. When a radio sector 104 in the wireless network is located instep 1910 using signals received through the primary antenna, the mobilewireless device 102 can compare the receive signal quality to thepre-determined first threshold in step 1920 to determine in which stateto sleep. When the receive signal quality exceeds the pre-determinedfirst threshold in step 1920, the mobile wireless device 102 can sleepin state S2 as indicated in step 1922. From state S2, the mobilewireless device 102 can awaken to decode page indicators 810/812 on thequick paging channel 806 using signals received through the primaryantenna as shown in FIG. 15. When the receive signal quality does notexceed the pre-determined first threshold in step 1920, the mobilewireless device 102 can sleep in state S1 as indicated in step 1924.From state S1, the mobile wireless device can awaken to decode thepaging channel 802 directly using signals received through the primaryantenna as shown in FIG. 14.

In another embodiment (not shown explicitly in FIG. 19), the mobilewireless device 102 can interrupt a full scan on the primary antenna instep 1908 periodically to perform a partial scan using the secondaryantenna. The periodic partial scans can use the same limited set ofradio sectors 104 as in step 1904 or can include additional logic tosearch for radio sectors 104 other than (or in addition to) the limitedset of radio sectors 104 used in step 1904. The full scan on the primaryantenna can be performed using an extensive list of radio sectors 104,while each partial scan on the secondary antenna can use a smaller listof radio sectors 104. The smaller list of radio sectors 104 used for thesecondary antenna can vary for each successive partial scan attemptcovering a broader list of radio sectors 104 over a number of separatepartial scans.

The various aspects, embodiments, implementations or features of thedescribed embodiments can be used separately or in any combination.Various aspects of the described embodiments can be implemented bysoftware, hardware or a combination of hardware and software.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the describedembodiments. However, it will be apparent to one skilled in the art thatthe specific details are not required in order to practice the describedembodiments. Thus, the foregoing descriptions of the specificembodiments described herein are presented for purposes of illustrationand description. They are not target to be exhaustive or to limit theembodiments to the precise forms disclosed. It will be apparent to oneof ordinary skill in the art that many modifications and variations arepossible in view of the above teachings.

The advantages of the embodiments described are numerous. Differentaspects, embodiments or implementations can yield one or more of thefollowing advantages. Many features and advantages of the presentembodiments are apparent from the written description and, thus, it isintended by the appended claims to cover all such features andadvantages of the invention. Further, since numerous modifications andchanges will readily occur to those skilled in the art, the embodimentsshould not be limited to the exact construction and operation asillustrated and described. Hence, all suitable modifications andequivalents can be resorted to as falling within the scope of theinvention.

What is claimed is:
 1. A method of adapting antenna receive diversity ina mobile wireless device in communication with a wireless network, themethod comprising: during a discontinuous reception cycle in the mobilewireless device, decoding at least one page indicator received on a pageindicator channel through an initial antenna when a measured downlinksignal quality exceeds a pre-determined threshold; decoding one or morepage messages received on a paging channel through the initial antennawithout decoding the page indicator channel when the measured downlinksignal quality does not exceed the pre-determined threshold; where thepaging channel and the page indicator channel are separate; decoding oneor more page messages received on the paging channel through analternate antenna when a first page indicator received on the pageindicator channel through the initial antenna decodes as an erasurevalue, where the erasure value indicates that an unequivocal value isnot present; and decoding one or more page messages received on thepaging channel through the initial antenna and through the alternateantenna together and ignoring the page indicator channel when no pagingmessage received on the paging channel through the initial antenna orthrough the alternate antenna alone decodes with a correct errorchecking code for a pre-determined period of time during thediscontinuous reception cycle.
 2. The method as recited in claim 1,further comprising: decoding one or more page messages received on thepaging channel through the initial antenna and through the alternateantenna together during a subsequent discontinuous reception cycle afterdecoding an incorrect error checking code in the current discontinuousreception cycle.
 3. The method as recited in claim 2, furthercomprising: ignoring the page indicator channel when decoding using theinitial antenna and the alternate antenna together.
 4. The method asrecited in claim 1, further comprising: switching from decoding thepaging channel with one antenna to decoding with multiple antennas aftermeasuring a first pre-determined number of incorrect consecutive errorchecking codes; and switching from decoding the paging channel withmultiple antennas to decoding the paging channel with one antenna aftermeasuring a second pre-determined number of correct consecutive errorchecking codes.
 5. The method as recited in claim 4, further comprising:measuring the second pre-determined number of correct consecutive errorchecking codes by counting consecutive discontinuous reception cyclesthat contain at least one correct error checking code and no incorrecterror checking codes.
 6. The method as recited in claim 1, furthercomprising: before decoding the at least one page indicators on the pageindicator channel, selecting the initial antenna from a plurality ofantennas based on a measurement of signal strength received through eachof the plurality of antennas.
 7. The method as recited in claim 1wherein the wireless network operates using a CDMA2000 1× communicationsprotocol.
 8. The method as recited in claim 7 wherein the error checkingcode is a layer 2 CRC segment of a layer 2 paging channel message.
 9. Amobile wireless device in communication with a wireless network andadapted for antenna receive diversity, comprising: a processorconfigured to, during a discontinuous reception cycle in the mobilewireless device: decode at least one page indicator received on a pageindicator channel through an initial antenna when a measured downlinksignal quality exceeds a pre-determined threshold; decode one or morepage messages received on a paging channel through the initial antennawithout decoding the page indicator channel when the measured downlinksignal quality does not exceed the pre-determined threshold; where thepaging channel and the page indicator channel are separate; decode oneor more page messages received on the paging channel through analternate antenna when a first page indicator received on the pageindicator channel through the initial antenna decodes as an erasurevalue, where the erasure value indicates that an unequivocal value isnot present; and decode one or more page messages received on the pagingchannel through the initial antenna and through the alternate antennatogether and ignoring the page indicator channel when no paging messagereceived on the paging channel through the initial antenna or throughthe alternate antenna alone decodes with a correct error checking codefor a pre-determined period of time during the discontinuous receptioncycle.
 10. The mobile wireless device as recited in claim 9, wherein theprocessor is further configured to: decode one or more page messagesreceived on the paging channel through the initial antenna and throughthe alternate antenna together during a subsequent discontinuousreception cycle after decoding an incorrect error checking code in thecurrent discontinuous reception cycle.
 11. The mobile wireless device asrecited in claim 10, wherein the processor is further configured to:ignore the page indicator channel when decoding using the initialantenna and the alternate antenna together.
 12. The mobile wirelessdevice as recited in claim 9, wherein the processor is furtherconfigured to: switch from decoding the paging channel with one antennato decoding with multiple antennas after measuring a firstpre-determined number of incorrect consecutive error checking codes; andswitch from decoding the paging channel with multiple antennas todecoding the paging channel with one antenna after measuring a secondpre-determined number of correct consecutive error checking codes. 13.The mobile wireless device as recited in claim 12, wherein the processoris further configured to: measure the second pre-determined number ofcorrect consecutive error checking codes by counting consecutivediscontinuous reception cycles that contain at least one correct errorchecking code and no incorrect error checking codes.
 14. The mobilewireless device as recited in claim 9, wherein the processor is furtherconfigured to: before decoding the at least one page indicators on thepage indicator channel, select the initial antenna from a plurality ofantennas based on a measurement of signal strength received through eachof the plurality of antennas.
 15. The mobile wireless device as recitedin claim 9, wherein: the wireless network operates using a CDMA2000 1×communications protocol; and the error checking code is a layer 2 CRCsegment of a layer 2 paging channel message.
 16. A non-transitorycomputer program product encoded in a non-transitory computer readablemedium for adapting antenna receive diversity in a mobile wirelessdevice in communication with a wireless network, the non-transitorycomputer program product comprising: in the mobile wireless device,during a discontinuous reception cycle, non-transitory computer programcode configured to: decode at least one page indicator received on apage indicator channel through an initial antenna when a measureddownlink signal quality exceeds a pre-determined threshold; decode oneor more page messages received on a paging channel through the initialantenna without decoding the page indicator channel when the measureddownlink signal quality does not exceed the pre-determined threshold;where the paging channel and the page indicator channel are separate;decode one or more page messages received on the paging channel throughan alternate antenna when a first page indicator received on the pageindicator channel through the initial antenna decodes as an erasurevalue, where the erasure value indicates that an unequivocal value isnot present; and decode one or more page messages received on the pagingchannel through the initial antenna and through the alternate antennatogether and ignoring the page indicator channel when no paging messagereceived on the paging channel through the initial antenna or throughthe alternate antenna alone decodes with a correct error checking codefor a pre-determined period of time during the discontinuous receptioncycle.
 17. The non-transitory computer program product as recited inclaim 16, wherein the non-transitory computer program code is furtherconfigured to: decode one or more page messages received on the pagingchannel through the initial antenna and through the alternate antennatogether during a subsequent discontinuous reception cycle afterdecoding an incorrect error checking code in the current discontinuousreception cycle.
 18. The non-transitory computer program product asrecited in claim 17, wherein the non-transitory computer program code isfurther configured to: ignore the page indicator channel when decodingusing the initial antenna and the alternate antenna together.
 19. Thenon-transitory computer program product as recited in claim 16, whereinthe non-transitory computer program code is further configured to:switch from decoding the paging channel with one antenna to decodingwith multiple antennas after measuring a first pre-determined number ofincorrect consecutive error checking codes; and switch from decoding thepaging channel with multiple antennas to decoding the paging channelwith one antenna after measuring a second pre-determined number ofcorrect consecutive error checking codes.
 20. The non-transitorycomputer program product as recited in claim 19, wherein thenon-transitory computer program code is further configured to: measurethe second pre-determined number of correct consecutive error checkingcodes by counting consecutive discontinuous reception cycles thatcontain at least one correct error checking code and no incorrect errorchecking codes.
 21. The non-transitory computer program product asrecited in claim 16, wherein the non-transitory computer program code isfurther configured to: before decoding the at least one page indicatorson the page indicator channel, select the initial antenna from aplurality of antennas based on a measurement of signal strength receivedthrough each of the plurality of antennas.
 22. The non-transitorycomputer program product as recited in claim 16, wherein: the wirelessnetwork operates using a CDMA2000 1×communications protocol; and theerror checking code is a layer 2 CRC segment of a layer 2 paging channelmessage.